Mitsubishi Electric MELSEC-A Series User manual

Transition from MELSEC-A/QnA (Large Type),
AnS/QnAS (Small Type) Series to Q Series
Handbook
(Network Modules)
Apr. 2018 Edition

A- 1
SAFETY PRECAUTIONS
(Read these precautions before using this product.)
Before using this product, please read this handbook and the relevant manuals introduced in this handbook
carefully and pay full attention to safety to handle the product correctly.
In this handbook, the safety precautions are classified into two levels: " WARNING" and " CAUTION".
Under some circumstances, failure to observe the precautions given under " CAUTION" may lead to
serious consequences.
Observe the precautions of both levels because they are important for personal and system safety.
Make sure that the end users read this handbook and then keep the handbook in a safe place for future
reference.
WARNING
CAUTION
Indicates that incorrect handling may cause hazardous conditions,
resulting in death or severe injury.
Indicates that incorrect handling may cause hazardous conditions,
resulting in minor or moderate injury or property damage.

A- 2
[Design Precautions]
WARNING
●For the operating status of each station after a communication failure in the data link or the network,
refer to the following manuals.
Failure to do so may result in an accident due to an incorrect output or malfunction.
• Q Corresponding MELSECNET/H Network System Reference Manual (PLC to PLC network)
• Q Corresponding MELSECNET/H Network System Reference Manual (Remote I/O network)
• Q Corresponding MELSECNET/H Remote I/O Module Reference Manual (MELSECNET/10
Mode)
• CC-Link System Master/Local Module User's Manual
●If a coaxial cable is disconnected, the network may be unstable, resulting in a communication failure
of multiple stations. Configure an interlock circuit in the program to ensure that the entire system will
always operate safely even if communications fail. Failure to do so may result in an accident due to
an incorrect output or malfunction.
●When connecting a peripheral with the CPU module or connecting a personal computer with an
intelligent function module to modify data of a running programmable controller, configure an
interlock circuit in the program to ensure that the entire system will always operate safely.
For other forms of control (such as program modification or operating status change) of a running
programmable controller, read the relevant manuals carefully and ensure that the operation is safe
before proceeding. Especially, when a remote programmable controller is controlled by an external
device, immediate action cannot be taken if a problem occurs in the programmable controller due to
a communication failure. To prevent this, configure an interlock circuit in the program, and determine
corrective actions to be taken between the external device and CPU module in case of a
communication failure.
●Do not write any data to the "system area" of the buffer memory in each intelligent function module.
Do not write any data to the "system area" of the buffer memory in the intelligent function module.
Also, do not use any "use prohibited" signals as an output signal from the CPU module to the
intelligent function module. Doing so may cause malfunction of the programmable controller system.
●To set the auto refresh parameter, select the device Y for the remote output (RY) refresh device.
If a device other than Y is selected, the CPU module holds the device status even after its status is
changed to STOP. For how to stop data link, refer to the following manual.
• CC-Link System Master/Local Module User's Manual
●If a CC-Link dedicated cable is disconnected, the network may be unstable, resulting in a
communication failure of multiple stations. Configure an interlock circuit in the program to ensure
that the entire system will always operate safely even if communications fail.
Failure to do so may result in an accident due to an incorrect output or malfunction.

A- 3
CAUTION
●After changing the parameter of the CPU module or the remote I/O module, reset the CPU module.
Failure to do so may cause malfunction, since the previous parameter setting remains in the module.
●Do not install the control lines or communication cables together with the main circuit lines or power
cables. Keep a distance of 100mm or more between them. Failure to do so may result in malfunction
due to noise.

A- 4
[Installation Precautions]
WARNING
●Shut off the external power supply (all phases) used in the system before mounting or removing a
module.
Failure to do so may result in electric shock or cause the module to fail or malfunction.
CAUTION
●Use the programmable controller in an environment that meets the general specifications in the
user’s manual for the CPU module used.
Failure to do so may result in electric shock, fire, malfunction, or damage to or deterioration of the
product.
●To mount a Q series module, while pressing the module mounting lever located in the lower part of
the module, fully insert the module fixing projection(s) into the hole(s) in the base unit and press the
module until it snaps into place.
Incorrect mounting may cause malfunction, failure or drop of the module.
When using the programmable controller in an environment of frequent vibrations, fix the module
with a screw.
Tighten the screw within the specified torque range.
Undertightening can cause drop of the screw, short circuit or malfunction.
Overtightening can damage the screw and/or module, resulting in drop, short circuit, or malfunction.
●To mount an A/AnS/QnA/QnAS module, fully insert the module fixing projection(s) located in the
lower part of the module into the hole(s) in the base unit and press the module until it snaps into
place (To fix an AnS series module to the base unit, tighten the screws within the specified torque
range).
Incorrect mounting may cause malfunction, failure or drop of the module.
●Shut off the external power supply (all phases) used in the system before mounting or removing the
module. Failure to do so may result in damage to the product.
●A MELSECNET/H module with function version D or later can be replaced online (while power is on)
on any remote I/O station. Note that there are restrictions on the modules that can be replaced
online, and each module has its predetermined replacement procedure.
For details, refer to the relevant section in the following.
• Q Corresponding MELSECNET/H Network System Reference Manual (Remote I/O network)
●Do not directly touch any conductive parts and electronic components of the module.
Doing so can cause malfunction or failure of the module.

A- 5
[Wiring Precautions]
WARNING
●Shut off the external power supply (all phases) used in the system before wiring.
Failure to do so may result in electric shock or cause the module to fail or malfunction.
●After installation and wiring, attach the included terminal cover to the module before turning it on for
operation.
Failure to do so may result in electric shock.
CAUTION
●Ground the FG terminal to the protective ground conductor dedicated to the programmable
controller. Failure to do so may result in malfunction.
●Check the rated voltage and terminal layout before wiring the external power supply terminal block,
and connect the cables correctly.
Connecting a power supply with a different voltage rating or incorrect wiring may cause a fire or
failure.
●Use applicable solderless terminals and tighten them within the specified torque range. If any spade
solderless terminal is used, it may be disconnected when the terminal screw comes loose, resulting
in failure.
●Correctly solder coaxial cable connectors. Incomplete soldering may result in malfunction.
●Do not install the control lines or communication cables together with the main circuit lines or power
cables.
Failure to do so may result in malfunction due to noise.
●Place the cables in a duct or clamp them.
If not, dangling cable may swing or inadvertently be pulled, resulting in damage to the module or
cables or malfunction due to poor contact.
●Tighten the terminal screw within the specified torque range.
Undertightening can cause short circuit or malfunction.
Overtightening can damage the screw and/or module, resulting in drop, short circuit, fire, or
malfunction.
●When disconnecting the cable from the module, do not pull the cable by the cable part.
For the cable with connector, hold the connector part of the cable.
For the cable connected to the terminal block, loosen the terminal block screws.
Pulling the cable connected to the module may result in malfunction and damage to the module or
cable.

A- 6
[Wiring Precautions]
[Startup and Maintenance Precautions]
CAUTION
●Mitsubishi Electric programmable controllers must be installed in control panels.
Connect the main power supply to the power supply module in the control panel through a relay
terminal block.
Wiring and replacement of a power supply module must be performed by qualified maintenance
personnel with knowledge of protection against electric shock. For wiring methods, refer to the
QCPU User's Manual (Hardware Design, Maintenance and Inspection).
●Prevent foreign matter such as dust or wire chips from entering the module.
Such foreign matter can cause a fire, failure, or malfunction.
●A protective film is attached to the top of the module to prevent foreign matter, such as wire chips,
from entering the module during wiring.
Do not remove the film during wiring.
Remove it for heat dissipation before system operation.
●Use CC-Link dedicated cables for the CC-Link system. If not, the performance of the CC-Link
system is not guaranteed.
For the maximum station-to-station distance and the overall cable distance, follow the specifications
in the following.
If not, normal data transmission will not be guaranteed.
• CC-Link System Master/Local Module User's Manual
WARNING
●Do not touch any terminal while power is on.
Doing so will cause electric shock or malfunction.
●Shut off the external power supply (all phases) used in the system before cleaning the module or
retightening the terminal screws or module fixing screws. Failure to do so may result in electric
shock.

A- 7
[Startup and Maintenance Precautions]
[Disposal Precautions]
CAUTION
●Before performing online operations (especially, program modification, forced output, and operating
status change) for the running CPU module on another station from GX Developer over the
MELSECNET/H network, read relevant manuals carefully and ensure the safety.
Improper operation may damage machines or cause accidents.
●Do not disassemble or modify the modules.
Doing so may cause failure, malfunction, injury, or a fire.
●Use any radio communication device such as a cellular phone or PHS (Personal Handy-phone
System) more than 25cm away in all directions from the programmable controller.
Failure to do so may cause malfunction.
●Shut off the external power supply (all phases) used in the system before mounting or removing a
module. Failure to do so may cause the module to fail or malfunction.
A MELSECNET/H module with function version D or later can be replaced online (while power is on)
on any remote I/O station.
Note that there are restrictions on the modules that can be replaced online, and each module has its
predetermined replacement procedure. For details, refer to the relevant section in the following
manual.
• Q Corresponding MELSECNET/H Network System Reference Manual (Remote I/O network)
●Do not touch any terminal while power is on.
Doing so will cause malfunction.
●Tighten the module fixing screw and the terminal screw within the specified torque range.
Undertightening can cause drop of the component or wire, short circuit, or malfunction.
Overtightening can damage the screw and/or module, resulting in drop, short circuit, or malfunction.
●After the first use of the product, do not mount/remove the module to/from the base unit, and the
terminal block to/from the module more than 50 times (IEC 61131-2 compliant) respectively.
Exceeding the limit of 50 times may cause malfunction.
●Before handling the module, touch a grounded metal object to discharge the static electricity from
the human body.
Failure to do so may cause the module to fail or malfunction.
CAUTION
●When disposing of this product, treat it as industrial waste.

A- 8
CONDITIONS OF USE FOR THE PRODUCT
(1) Mitsubishi programmable controller ("the PRODUCT") shall be used in conditions;
i) where any problem, fault or failure occurring in the PRODUCT, if any, shall not lead to any major
or serious accident; and
ii) where the backup and fail-safe function are systematically or automatically provided outside of
the PRODUCT for the case of any problem, fault or failure occurring in the PRODUCT.
(2) The PRODUCT has been designed and manufactured for the purpose of being used in general
industries.
MITSUBISHI SHALL HAVE NO RESPONSIBILITY OR LIABILITY (INCLUDING, BUT NOT
LIMITED TO ANY AND ALL RESPONSIBILITY OR LIABILITY BASED ON CONTRACT,
WARRANTY, TORT, PRODUCT LIABILITY) FOR ANY INJURY OR DEATH TO PERSONS OR
LOSS OR DAMAGE TO PROPERTY CAUSED BY the PRODUCT THAT ARE OPERATED OR
USED IN APPLICATION NOT INTENDED OR EXCLUDED BY INSTRUCTIONS, PRECAUTIONS,
OR WARNING CONTAINED IN MITSUBISHI'S USER, INSTRUCTION AND/OR SAFETY
MANUALS, TECHNICAL BULLETINS AND GUIDELINES FOR the PRODUCT.
("Prohibited Application")
Prohibited Applications include, but not limited to, the use of the PRODUCT in;
• Nuclear Power Plants and any other power plants operated by Power companies, and/or any
other cases in which the public could be affected if any problem or fault occurs in the PRODUCT.
• Railway companies or Public service purposes, and/or any other cases in which establishment of
a special quality assurance system is required by the Purchaser or End User.
• Aircraft or Aerospace, Medical applications, Train equipment, transport equipment such as
Elevator and Escalator, Incineration and Fuel devices, Vehicles, Manned transportation,
Equipment for Recreation and Amusement, and Safety devices, handling of Nuclear or
Hazardous Materials or Chemicals, Mining and Drilling, and/or other applications where there is a
significant risk of injury to the public or property.
Notwithstanding the above, restrictions Mitsubishi may in its sole discretion, authorize use of the
PRODUCT in one or more of the Prohibited Applications, provided that the usage of the PRODUCT
is limited only for the specific applications agreed to by Mitsubishi and provided further that no
special quality assurance or fail-safe, redundant or other safety features which exceed the general
specifications of the PRODUCTs are required. For details, please contact the Mitsubishi
representative in your region.

A- 9
REVISIONS
* The handbook number is given on the bottom left of the back cover.
Japanese Handbook Version L-08047-P
© 2005 MITSUBISHI ELECTRIC CORPORATION
Print Date * Handbook Number Revision
Apr. 2005 L(NA)08048ENG-A First edition
Oct. 2005 L(NA)08048ENG-B
Section 1.1.3, Section 2.5.3, Section 2.5.4, Appendix 1
Contents, Section 2.5.2, Section 2.7, Section 3.5.2, Appendix 1Appendix 2
Oct. 2006 L(NA)08048ENG-C
Chapter 6
Section 1.3, Chapter 6Chapter 7, Chapter 7Chapter 8
Jul. 2007 L(NA)08048ENG-D
Section 1.1.4, Chapter 7
Section 1.1.3, Chapter 7Chapter 8, Chapter 8Chapter 9
Nov. 2012 L(NA)08048ENG-E Revision on the new functions of the Universal model QCPU with a serial number
(first five digits) of "13102" or later
QJ71NT11B, MELSEC-AnS/QnAS series, QA1S51B, 5C-FB
SAFETY PRECAUTIONS, Chapter 1 to 9, Appendix
Mar. 2016 L(NA)08048ENG-F
Section 5.2
Chapter 9 Appendix 1, Appendix 1 Appendix 2, Appendix 2 Appendix 3
Cover, Section 1.1, 1.1.3, 1.2, 2.6.2, 4.1, 4.2, 4.4, 4.5, 4.6.2, 5.1, 7.4, Appendix
3.4, WARRANTY
Apr. 2018 L(NA)08048ENG-G
Chapter 6, 7
Chapter 8 Chapter 6
SAFETY PRECAUTIONS, GENERIC TERMS AND ABBREVIATIONS, Section
1.1, 2.3, 2.4, 2.5, 2.7, 3.3, 3.4, 3.5.2, 3.7, 4.3, 4.4, 4.5, 5.1, 5.2.4, 6.1, 6.2.1,
Appendix 3.1, 3.4
This handbook confers no industrial property rights or any rights of any other kind, nor does it confer any patent licenses.
Mitsubishi Electric Corporation cannot be held responsible for any problems involving industrial property rights which may
occur as a result of using the contents noted in this handbook.
Addition
Partial correction
Addition
Partial correction
Addition
Partial correction
Model Addition
Partial correction
Addition
Change
Partial correction
Deletion
Change
Partial correction

A- 10
SAFETY PRECAUTIONS ................................................................................................................................A - 1
CONDITIONS OF USE FOR THE PRODUCT .................................................................................................A - 8
REVISIONS ......................................................................................................................................................A - 9
CONTENTS ...................................................................................................................................................A - 10
GENERIC TERMS AND ABBREVIATIONS ...................................................................................................A - 14
CHAPTER 1 INTRODUCTION 1 - 1 to 1 - 20
1.1 Transition from MELSECNET (II) and /B to MELSECNET/H ........................................................... 1 - 1
1.1.1 Transition to the Q series .......................................................................................................... 1 - 1
1.1.2 Transition procedure to a Q series MELSECNET/H system .................................................. 1 - 13
1.1.3 Replacement selection points ................................................................................................. 1 - 14
1.2 Replacement of the MELSECNET/10 for A/AnS/QnA/QnAS Series with the MELSECNET/H for
Q Series ......................................................................................................................................... 1 - 16
1.3 Replacing the CC-Link for A/AnS/QnA/QnAS Series with the CC-Link for Q Series ..................... 1 - 20
CHAPTER 2 REPLACEMENT OF MELSECNET (II) AND /B (PLC TO PLC NETWORK)
2 - 1 to 2 - 75
2.1 List of MELSECNET (II) and /B Alternative Models ......................................................................... 2 - 1
2.2 Performance Specifications Comparisons ....................................................................................... 2 - 3
2.2.1 Module performance comparisons ........................................................................................... 2 - 3
2.2.2 Cable performance comparisons .............................................................................................. 2 - 7
2.3 Functional Comparisons ................................................................................................................ 2 - 10
2.4 Switch Settings Comparisons ........................................................................................................ 2 - 11
2.5 Parameter Comparisons ................................................................................................................ 2 - 12
2.5.1 Parameter comparisons .......................................................................................................... 2 - 12
2.5.2 Example of changing parameters on 2-tier system ................................................................ 2 - 13
2.5.3 Example of changing parameters on 3-tier system (When only the first half of link parameter
is set) ...................................................................................................................................... 2 - 27
2.5.4 Example of changing parameters on 3-tier system (When the first half/second half of link
parameter is set) ..................................................................................................................... 2 - 43
2.6 Program Comparisons ................................................................................................................... 2 - 63
2.6.1 Comparison of special relays M (SB) and special registers D (SW) ....................................... 2 - 63
2.6.2 Transient instructions .............................................................................................................. 2 - 70
2.7 Replacement Precautions .............................................................................................................. 2 - 72
CHAPTER 3 REPLACEMENT OF MELSECNET (II) AND /B (REMOTE I/O NETWORK)
3 - 1 to 3 - 29
3.1 List of MELSECNET (II) and /B Alternative Models ......................................................................... 3 - 1
3.2 Performance Specifications Comparisons ....................................................................................... 3 - 3
3.2.1 Module performance Compatibility comparisons ...................................................................... 3 - 3
CONTENTS

A- 11
3.2.2 Cable performance comparisons .............................................................................................. 3 - 8
3.3 Functional Comparisons ................................................................................................................ 3 - 10
3.4 Switch Settings Comparisons ........................................................................................................ 3 - 11
3.5 Parameter Comparisons ................................................................................................................ 3 - 12
3.5.1 Parameter comparisons ......................................................................................................... 3 - 12
3.5.2 Parameter change example ................................................................................................... 3 - 13
3.6 Program Comparisons ................................................................................................................... 3 - 23
3.6.1 Comparison of special relays M (SB) and special registers D (SW) ...................................... 3 - 23
3.6.2 Transient instructions ............................................................................................................. 3 - 27
3.7 Replacement Precautions .............................................................................................................. 3 - 28
CHAPTER 4 REPLACEMENT OF THE MELSECNET/10 (PLC TO PLC NETWORK)
4 - 1 to 4 - 25
4.1 List of MELSECNET/10 Alternative Models .....................................................................................4-1
4.2 Performance Specifications Comparisons ....................................................................................... 4 - 2
4.2.1 Module performance comparisons incompatible ...................................................................... 4 - 2
4.2.2 Cable performance comparisons .............................................................................................. 4 - 8
4.3 Functional Comparisons ................................................................................................................ 4 - 10
4.4 Switch Settings Comparisons ........................................................................................................ 4 - 14
4.5 Parameter Comparisons ................................................................................................................ 4 - 15
4.6 Program Comparisons ................................................................................................................... 4 - 18
4.6.1 Comparison of link special relay (SB)/link special register (SW) ............................................ 4 - 18
4.6.2 Comparison of dedicated instructions .................................................................................... 4 - 21
4.7 Other Precautions .......................................................................................................................... 4 - 25
CHAPTER 5 REPLACEMENT OF THE MELSECNET/10 (REMOTE I/O NETWORK)
5 - 1 to 5 - 47
5.1 Replacing MELSECNET/10 with MELSECNET/H ........................................................................... 5 - 1
5.1.1 List of MELSECNET/10 alternative models .............................................................................. 5 - 1
5.1.2 Performance specifications comparisons ................................................................................. 5 - 3
5.1.3 Functional Comparisons ......................................................................................................... 5 - 18
5.1.4 Switch setting comparisons .................................................................................................... 5 - 22
5.1.5 Parameter comparisons ......................................................................................................... 5 - 24
5.1.6 Program comparisons ............................................................................................................ 5 - 29
5.1.7 Comparison of dedicated instruction ...................................................................................... 5 - 30
5.1.8 Other precautions ................................................................................................................... 5 - 35
5.2 Gradually replacing A series remote I/O stations with Q series remote I/O stations ..................... 5 - 36
5.2.1 List of MELSECNET/10 modules and the alternative modules .............................................. 5 - 36
5.2.2 Module performance specifications comparisons ................................................................... 5 - 38
5.2.3 Functional comparisons .......................................................................................................... 5 - 41
5.2.4 Switch setting comparisons .................................................................................................... 5 - 42
5.2.5 Parameter comparisons ......................................................................................................... 5 - 43
5.2.6 Program comparisons ............................................................................................................ 5 - 44
5.2.7 Last stage of the replacement ................................................................................................ 5 - 47

A- 12
CHAPTER 6 REPLACEMENT OF CC-LINK 6 - 1 to 6 - 27
6.1 List of CC-Link Alternative Models ................................................................................................... 6 - 1
6.2 Performance Specifications Comparisons ....................................................................................... 6 - 2
6.2.1 Module performance comparisons ........................................................................................... 6 - 2
6.2.2 Cable performance comparisons .............................................................................................. 6 - 4
6.3 Functional Comparisons .................................................................................................................. 6 - 5
6.4 Switch Settings Comparisons .......................................................................................................... 6 - 9
6.5 Parameter Comparisons ................................................................................................................ 6 - 11
6.6 Program Comparisons ................................................................................................................... 6 - 12
6.6.1 Comparison of I/O signals ...................................................................................................... 6 - 12
6.6.2 Buffer memory comparisons ................................................................................................... 6 - 16
6.6.3 Comparison of link special relay (SB)/link special register (SW) ............................................ 6 - 18
6.7 Other Precautions .......................................................................................................................... 6 - 24
6.8 Parameter Setting Example ........................................................................................................... 6 - 25
6.8.1 Parameter setting example on the A/AnS series .................................................................... 6 - 25
6.8.2 Parameter setting example on the Q series ........................................................................... 6 - 27
APPENDICES APPX - 1 to APPX - 4
Appendix 1 External Dimensions .......................................................................................................APPX - 1
Appendix 2 Spare parts storage ........................................................................................................APPX - 1
Appendix 3 Related Manuals .............................................................................................................APPX - 3
Appendix 3.1 Replacement handbooks .........................................................................................APPX - 3
Appendix 3.2 A/AnS series ............................................................................................................APPX - 4
Appendix 3.3 QnA/QnAS series ....................................................................................................APPX - 4
Appendix 3.4 Q series ...................................................................................................................APPX - 4

A- 13
●For the products shown in handbooks for transition, catalogues, and transition examples, refer to the
manuals for the relevant products and check the detailed specifications, precautions for use, and
restrictions before replacement.
For the products manufactured by Mitsubishi Electric Engineering Co., Ltd., Mitsubishi Electric
System & Service Co., Ltd., and other companies, refer to the catalogue for each product and check
the detailed specifications, precautions for use, and restrictions before use.
The manuals and catalogues for our products, products manufactured by Mitsubishi Electric
Engineering Co., Ltd., and Mitsubishi Electric System & Service Co., Ltd. are shown in Appendix of
each handbook for transition.
●Products shown in this handbook are subject to change without notice.

A- 14
GENERIC TERMS AND ABBREVIATIONS
Unless otherwise specified, this handbook uses the following generic terms and abbreviations.
Generic term/abbreviation Description
Series
A series Abbreviation for large types of Mitsubishi Electric MELSEC-A series programmable controllers
AnS series Abbreviation for compact types of Mitsubishi Electric MELSEC-A series programmable
controllers
A/AnS series Generic term for A series and AnS series
QnA series Abbreviation for large types of Mitsubishi Electric MELSEC-QnA series programmable
controllers
QnAS series Abbreviation for compact types of Mitsubishi Electric MELSEC-QnA series programmable
controllers
QnA/QnAS series Generic term for QnA series and QnAS series
A/AnS/QnA/QnAS series Generic term for A series, AnS series, QnA series, and QnAS series
Q series Abbreviation for Mitsubishi Electric MELSEC-Q series programmable controllers
CPU module type
CPU module Generic term for A series, AnS series, QnA series, QnAS series, and Q series CPU modules
Process CPU Generic term for the Q02PHCPU, Q06PHCPU, Q12PHCPU, and Q25PHCPU
Redundant CPU Generic term for the Q12PRHCPU and Q25PRHCPU
Universal model QCPU
Generic term for the Q00UJCPU, Q00UCPU, Q01UCPU, Q02UCPU, Q03UDCPU,
Q03UDVCPU, Q03UDECPU, Q04UDHCPU, Q04UDVCPU, Q04UDEHCPU, Q06UDHCPU,
Q06UDVCPU, Q06UDEHCPU, Q10UDHCPU, Q10UDEHCPU, Q13UDHCPU, Q13UDVCPU,
Q13UDEHCPU, Q20UDHCPU, Q20UDEHCPU, Q26UDHCPU, Q26UDVCPU, and
Q26UDEHCPU
CPU module model
ACPU Generic term for MELSEC-A series programmable controller CPUs
AnSCPU Generic term for MELSEC-AnS series programmable controller CPUs
A/AnSCPU Generic term for MELSEC-A series and MELSEC-AnS series programmable controller CPUs
AnNCPU
Generic term for the A1NCPU, A1NCPUP21/R21, A1NCPUP21-S3, A2NCPU, A2NCPU-S1,
A2NCPUP21/R21, A2NCPUP21/R21-S1, A2NCPUP21-S3(S4), A3NCPU, A3NCPUP21/R21,
and A3NCPUP21-S3
AnACPU Generic term for the A2ACPU, A2ACPU-S1, A3ACPU, A2ACPUP21/R21, A2ACPUP21/R21-
S1, and A3ACPUP21/R21
AnUCPU Generic term for the A2UCPU, A2UCPU-S1, A3UCPU, A4UCPU, A2USCPU, A2USCPU-S1,
and A2USHCPU-S1
AnN/AnACPU Generic term for the AnNCPU and AnACPU
AnN/AnA/AnSCPU Generic term for the AnNCPU, AnACPU, and AnSCPU
QnACPU Generic term for MELSEC-QnA series programmable controller CPUs
QnASCPU Generic term for MELSEC-QnAS series programmable controller CPUs
QnA/QnASCPU Generic term for MELSEC-QnA series and MELSEC-QnAS series programmable controller
CPUs
A/AnS/QnA/QnASCPU Generic term for A series, AnS series, QnA series, and QnAS series programmable controller
CPUs
QCPU Generic term for MELSEC-Q series programmable controller CPUs

A- 15
[About symbols used in figures]
MELSECNET( II ) MELSECNET/H
stands for the station No. stands for the network No., and
stands for the station No.
mM Master station lL Local station
rR Remote I/O station
MP
Control station
M R
Remote master station
N S
Normal station
RRemote I/O station

INTRODUCTION
1- 1
1
1.1.1 Transition to the Q series
To replace the MELSECNET (II) and /B system with the Q series system, replace it with the
MELSECNET/H system.
For a replacement method, refer to Section 1.1.2.
The following shows the configuration of the Q series MELSECNET/H system after the transition and
the system configuration precautions at transition for each of the MELSECNET (II) and /B system
configurations.
For details, refer to CHAPTER 2 and CHAPTER 3.
1
1 INTRODUCTION
1.1 Transition from MELSECNET (II) and /B to MELSECNET/H
Network type 2-tier/3-tier Component stations Refer to
Optical loop
2-tier system
Local station only Section 1.1.1 (1) (a)
Remote I/O station only Section 1.1.1 (1) (b)
Mixture of local station and remote I/O station Section 1.1.1 (1) (c)
3-tier system
Local station only Section 1.1.1 (1) (d)
2-tier local station, 3-tier remote I/O station Section 1.1.1 (1) (e)
Mixture of local station and remote I/O station Section 1.1.1 (1) (f)
Coaxial loop
2-tier system
Local station only Section 1.1.1 (2) (a)
Remote I/O station only Section 1.1.1 (2) (b)
Mixture of local station and remote I/O station Section 1.1.1 (2) (c)
3-tier system
Local station only Section 1.1.1 (2) (d)
2-tier local station, 3-tier remote I/O station Section 1.1.1 (2) (e)
Mixture of local station and remote I/O station Section 1.1.1 (2) (f)
Twisted pair
2-tier system
Local station only Section 1.1.1 (3) (a)
Remote I/O station only Section 1.1.1 (3) (b)
Mixture of local station and remote I/O station Section 1.1.1 (3) (c)
3-tier system
Local station only Section 1.1.1 (3) (d)
2-tier local station, 3-tier remote I/O station Section 1.1.1 (3) (e)
Mixture of local station and remote I/O station Section 1.1.1 (3) (f)

1- 2
INTRODUCTION
1
(1) Optical cable system
(a) 2-tier system 1: System configuration example using local stations only
*1 As the transmission speed of MELSECNET/H is faster than that of MELSECNET(II), the distance between stations may
become shorter.
(b) 2-tier system 2: System configuration example using remote I/O stations only
*1 As the transmission speed of MELSECNET/H is faster than that of MELSECNET(II), the distance between stations may
become shorter.
MELSECNET( II ) MELSECNET/H System configuration precautions
Optical loop Optical loop
1) Distance between stations: If this value
exceed the Q series specification values
when re-using the MELSECNET(II)
system cables, optical cables, etc. has to
be changed.*1
2) CPU: When replacing from an integrated
type CPU, one new slot (32 points) is
required.
3) Number of stations: When 65 modules
are connected, measures (e.g. dividing
into two networks of 64 modules or less
having a different network No.) are
required.
MELSECNET( II ) MELSECNET/H System configuration precautions
Optical loop Optical loop 1) Distance between stations: If this value
exceed the Q series specification values
when re-using the MELSECNET(II)
system cables, optical cables, etc. has to
be changed.*1
2) CPU: When replacing from an integrated
type CPU, one new slot (32 points) is
required.
L3L1
M
L2
Network 1 1NS31NS1
1MP4
1NS2
R3R1
M
R2
Network 1 1R31R1
1MR
1R2

INTRODUCTION
1- 3
1
(c) 2-tier system 3: System configuration example using local stations/remote I/O stations
*1 As the transmission speed of MELSECNET/H is faster than that of MELSECNET(II), the distance between stations may
become shorter.
(d) 3-tier system 1: System configuration example using local stations only
*1 As the transmission speed of MELSECNET/H is faster than that of MELSECNET(II), the distance between stations may
become shorter.
MELSECNET( II ) MELSECNET/H System configuration precautions
Optical loop
Optical loop
1) Distance between stations: If this value
exceed the Q series specification values
when re-using the MELSECNET(II)
system cables, optical cables, etc. has to
be changed.*1
2) CPU: When replacing from an integrated
type CPU, one new slot (32 points) is
required.
3) Composite system: As a mixture of a PLC
to PLC network and a remote I/O network
is not allowed on the Q series, the
network has to be divided into two
networks having different network Nos.
For this reason, a separate network
module for the remote master station is
required.
4) New installation: A separate optical cable
is required for the remote I/O stations.
MELSECNET( II ) MELSECNET/H System configuration precautions
Optical loop Optical loop 1) Distance between stations: If this value
exceed the Q series specification values
when re-using the MELSECNET(II)
system cables, optical cables, etc. has to
be changed.*1
2) CPU: When replacing from an integrated
type CPU, one new slot (32 points) is
required.
3) Number of stations: When 65 modules
are connected, measures (e.g. dividing
into two networks of 64 modules or less
having a different network No.) are
required.
R3L1
M
L2
1NS1
1NS2
Network
22R3
1MP4/2MR
Network
1
I2
I3I1
L3L1
M
L2/m
2NS2
Network 2 2NS32NS1
Network 1 1NS31NS1
1MP4
1NS2/2MP4